Innumerable widely varying proposals have been made heretofore for providing internal combustion engines with the most efficient and precisely controlled conditions to meet the wide range operating requirements of internal combustion engines. These proposals fall into many categories including carburetors utilizing float controlled fuel bowls, both mechanically and electronically controlled fuel injection systems, systems using gaseous fuel supplied from pressurized tanks or converted to gas from a pressurized liquid supply, and carburetion systems designed to release pressurized fuel into the air intake passage via an operator-controlled metering valve.
This invention relates to the last mentioned category, different illustrated embodiments of which are disclosed in my prior U.S. Pat. Nos. 2,846,597; 3,053,242; 3,224,425; and 3,373,725. The objective sought to be served in each of these constructions was the avoidance of certain shortcomings and disadvantages of prior carbureting systems, particularly those in widespread use in automotive equipment and utilizing float bowl type carburetors. Other important objectives were to provide for most positive control of a fuel and a very substantial reduction in the release of unburned fuel to the atmosphere including smog producing constituents. In my three earlier patents listed above, these objectives were served in major part by cutting off all fuel flow during major portions of vehicle coasting and deceleration with the provision of means for automatically resuming fuel supply and restarting the engine as the vehicle approached a stop condition.
My latest and last issued patent avoided the anticipated reluctance of drivers to be on the highway with a non-operating engine during coasting and deceleration by eliminating the temporary fuel cut-off feature but, as in each of my patents, this carburetor also relied upon flow sensing means in the carburetor air intake passage. Such movable flow sensing means objectionably obstruct the efficient flow of fuel and air and introduce inherently delay and provide slow response to the desired rapid response to fuel enriching and leaning needs for smooth and high efficient engine operation. These prior pressure sensing expedients also cause rough engine operation, stumbling and stalling.